Cancer

X-ray therapy for cancer treatment, Guy's Hospital, London, 1925.

The ancient Greek physician Hippocrates coined the term ‘cancer’ after the shape of crab-like extensions of veins from tumours. Explanations of the origin of cancer reflect the medical theories of their time. In ancient Greece and Rome, doctors argued that cancer was caused by humoral imbalances. In the Renaissance, advocates of iatrochemistry such as Paracelsus preferred explanations based on chemical origins. In the 1800s advances in microscopy allowed scientists to observe diseases at the cell level, and they found that cancer was the abnormally rapid, uncontrolled growth of cells in the body, invading and damaging healthy body tissue in the process.

For thousands of years, the treatment of cancer was mostly restricted to the surgical removal of tumours, rarely resulting in the patient's recovery. Following the discovery of X-rays in 1895 and of the radioactive element radium in 1898, scientists noticed that some forms of radiation could be used to destroy cancer cells, and they promoted radiotherapy as a new form of cancer treatment. In the 1940s and 1950s researchers developed chemotherapy as a cancer treatment. However, both radiotherapy and chemotherapy remain problematic to the present day. Radiation and chemicals used to destroy cancer cells also damage normal cells in the body, leading to side effects including vomiting and hair loss.

Today researchers are trying to develop other forms of treatment such as the use of genetically engineeredantibodies and hormones. At present, cancer patients are usually treated with a combination of different methods.